Bismuth oxybromide (BiOBr) nanosheets are exciting photocatalysts for microbial disinfection and organic dye degradation. However, it remains a great challenge to easily recycle these nanomaterials and improve their photocatalytic ability. Herein, we constructed a novel photocatalytic BiOBr@PAG gel containing BiOBr nanosheets and polyacrylamide gel (PAG), based on peroxydisulfate-induced polymerization reaction. The photocatalytic gel had equally distribution of BiOBr nanosheets on the surface, and could be easily recycled from water. More strikingly, the gel could also rapidly kill all tested pathogenic bacteria (i. e., Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) under irradiation. Its disinfection activity is attributed to remarkable intracellular ROS production and oxidative cell damage. Furthermore, the gel had higher photocatalytic activity than BiOBr nanosheets alone during degradation of organic dyes. This study developed a novel strategy for preparation of easy-recycling and high-efficiency photocatalytic systems for practical application in environmental treatment and medicinal disinfection. 相似文献
Phosphoaluminate cement (PAC) clinker had good mechanical properties at early and long-term period. In comparison, the compressive strength of PAC clinker modified by BaO was more prominent. As primary mineral phase for PAC clinker, CA’s mineralogical structure and hydration characteristics were intimately related to the compressive strength of hardened cement paste. In this study, the effects of BaO content on the calcination, mineralogical structure and hydration characteristics of CA were investigated. Experimental results showed that the appropriate calcination temperature of CA was 1400 °C. No more than 11% (the substitution ratio of BaO for CaO) addition of BaO can promote the conversion of C12A7 to CA and increase the formation ratio of CA. Appropriate content of 7 mol% BaO could endow the hardened paste with excellent compressive strength. In CA mineral phase the high limit addition of BaO was 15 mol%. The addition of BaO decreased and even restrained the formation of C2AH8 and C3AH6 of CA hydration products and also improved the content of CAH10. The addition of BaO dramatically decreased the hydration velocity and cumulative heat of CA mineral.
The linker 1,4-bis(2-methyl-imidazole-yl)-butane (bib) was used to construct two coordination polymers, specifically [Cd(bib)(ipa)]n (1) and [Zn(bib)(tpa)]n (2), in the presence of isophthalic acid (H2ipa) and terephthalic acid (H2tpa), respectively, under solvothermal conditions. Topological analyses reveal that the crystal of complex 1 consists of a 3D threefold interpenetrating network with Schläfli symbol {65.8}, while complex 2 possesses a 2D wavelike layer structure with Schläfli symbol {66}. The photocatalytic properties of both complexes for the degradation of methyl violet have been explored, revealing that complex 2 is a better photocatalyst than 1. A mechanism for the photocatalytic properties of the complexes is proposed, based on the results of density of states (DOS) and partial DOS calculations.
Investigating the structures and properties of Au-Ge mixed clusters can give insight into the microscopic mechanisms in gold-catalyzed Ge films and can also provide valuable information for the production of germanium-based functional materials. In this work, size-selected anion photoelectron spectroscopy and theoretical calculations were used to explore the structural evolution and electronic properties of Au2Gen-/0 (n=1-8) clusters. It is found that the two Au atoms in Au2Gen-/0 (n=1-8) showed high coordination numbers and weak aurophilic interactions. The global minima of Au2Gen- anions and Au2Gen neutrals are in spin doublet and singlet states, respectively. Au2Gen- anions and Au2Gen neutrals showed similar structural features, except for Au2Ge4-/0 and Au2Ge5-/0. The C2v symmetric V-shaped structure is observed for Au2Ge1-/0, while Au2Ge2-/0 has a C2v symmetric dibridged structure. Au2Ge3-/0 can be viewed as the two Au atoms attached to different Ge-Ge bonds of Ge3 triangle. Au2Ge4- has two Au atoms edge-capping Ge4 tetrahedron, while Au2Ge4 neutral adopts a C2v symmetric double Au atoms face-capping Ge4 rhombus. Au2Ge5-8-/0 show triangular, tetragonal, and pentagonal prism-based geometries. Au2Ge6 adopts a C2v symmetric tetragonal prism structure and exhibits σ plus π double bonding characters. 相似文献
The adsorption characteristics of phosphorylated Aspergillus niger (AN-P) for uranium(VI) were studied in this work. The AN-P was successfully prepared by the reaction of Aspergillus niger with phosphorus pentoxide in ice-bath under the catalysis of methanesulphonic acid. AN-P was characterized by FT-IR and SEM–EDS. The effects of pH, contact time, initial U(VI) ions concentration, adsorbent dosage and temperature on the adsorption of U(VI) by AN-P were investigated. The isotherm and kinetic data were accurately described by the Langmuir and pseudo-second-order models, respectively. The calculated thermodynamic parameters indicated that the adsorption of U(VI) by AN-P was an spontaneous and endothermic process. This indicated that the AN-P composite is a promising adsorbent for efficient removal of U(VI) from radioactive wastewater.
Hot carriers (HCs) and thermal effects, stemming from plasmon decays, are crucial for most plasmonic applications. However, quantifying these two effects remains extremely challenging due to the experimental difficulty in accurately measuring the temperature at reaction sites. Herein, we provide a novel strategy to disentangle HCs from photothermal effects based on the different traits of heat dissipation (long range) and HCs transport (short range), and quantitatively uncover the dominant and potential-dependent role of photothermal effect by investigating the rapid- and slow-response currents in plasmon-mediated electrochemistry at nanostructured Ag electrode. Furthermore, the plasmoelectric surface potential is found to contribute to the rapid-response currents, which is absent in the previous studies. 相似文献
Biological ion channels and ion pumps with sub-nanometer sizes modulate ion transport in response to external stimuli. Realizing such functions with sub-nanometer solid-state nanopores has been an important topic with wide practical applications. Herein, we demonstrate a biomimetic photoresponsive ion channel and photodriven ion pump using a porphyrin-based metal–organic framework membrane with pore sizes comparable to hydrated ions. We show that the molecular-size pores enable precise and robust optoelectronic ion transport modulation in a broad range of concentrations, unparalleled with conventional solid-state nanopores. Upon decoration with platinum nanoparticles to form a Schottky barrier photodiode, photovoltage across the membrane is generated with “uphill” ion transport from low concentration to high concentration. These results may spark applications in energy conversion, ion sieving, and artificial photosynthesis. 相似文献
Hierarchically porous metal–organic frameworks (HP-MOFs) are promising in various applications. Most reported HP-MOFs are prepared based on the generation of mesopores in microporous frameworks, and the formed mesopores are connected by microporous channels, limiting the accessibility of mesopores for bulky molecules. A hierarchical structure is formed by constructing microporous MOFs in uninterrupted mesoporous tunnels. Using the confined space in as-prepared mesoporous silica, highly dispersed metal precursors for MOFs are coated on the internal surface of mesoporous tunnels. Ligand vapor-induced crystallization is employed to enable quantitative formation of MOFs in situ, in which sublimated ligands diffuse into mesoporous tunnels and react with metal precursors. The obtained hierarchically porous composites exhibit record-high adsorption capacity for the bulky molecule trypsin. The thermal and storage stability of trypsin is improved upon immobilization on the composites. 相似文献
Defect passivation is an important strategy to achieve perovskite solar cells(PVSCs) with enhanced power conversion efficiencies(PCEs) and improved stability because the trap states induced by defects in the interfaces and grain boundaries of perovskites are harmful to both large open circuit voltage and high photocurrent of devices. Here, zinc cations(Zn~(2+)) were used as a dopant to passivate defects of the CsPbI_2Br perovskite leading to Zn~(2+)-doped CsPbI_2Br film with fewer trap states, improved charge transportation, and enhanced light-harvesting ability. Thus, the best-performance PVSC based on CsPbI2 Br with the optimal Zn~(2+)doping shows a higher PCE of 12.16% with a larger open-circuit voltage(V_(OC)) of 1.236 V, an improved shortcircuit current(J_(SC)) of 15.61 mA cm~(-2) in comparison with the control device based on the pure CsPbI_2Br which exhibits a PCE of 10.21% with a V_(OC)of 1.123 V, a J_(SC)of 13.27 mA cm~(-2). Time-resolved photoluminescence results show that the Zn~(2+)doping leads to perovskite film with extended photoluminescence lifetime which means a longer diffusion length and subsequently enhanced photocurrent and open circuit voltage. This work provides a simple strategy to boost the performance of PVSCs through Zn~(2+)doping. 相似文献